Composite sheet material



June 19, 1923.

o. D. RICHARDSON COMPOSITE SHEET MATERIAL Filed Jan. 50, 1922 I/VVE/VTORI Patented June 19, 11323.

COMPOSITE SHEET I MATERIAL.

Application filed January 30, 1922, Serial No. 532,642.

T all whom it may concern:

Be it known that I, 01210 D. RICHARD- SON, a citizen of the United States, residing at Chicago, in the county of Cook and State a of Illinois, have invented new and useful Improvements in Composite Sheet Materials, of which the following is a full,

clear, concise, and exact description, reference being had to the accompanying drawing, forming apart of this specification.

My invention relates to composite sheet material, such as may be used for roofing, flooring, weather-proofing, sheathing, etc, also for making boxes, cartons, etc., also wherever a sheet material fabric is desired having comparatively great tensile strength. One of the objects of my invention is to provide an improved compositesheet material which will be tougher and more due rable than sheets heretofore used. 7

A further object of my invention is to provide an improved method for forming such sheets, and improved apparatus for use inthe manufacture of said sheets.

Further objects will appear from the detailed description to follow and from the appended claims.

In the drawing in which my invention is illustrated- Fi re 1 is a diagrammatic side elevationa view showing apparatus for forming a composite sheet;

Fig. 2 is a very much enlarged perspective view showing a portion of the sheet 35 formed; and

Fig. 3 is a very much enlarged perspective view showing a sheet'of somewhat different composition from that shown in Fig. 2

he i In carrying out my invention I may make use of known apparatus, such as already in use for manufacture of a built-up felted fabric, adding to this known apparatus means whereb fibrous material, such as sisal or the li e, will be embedded in the felted fabric, while the fabric is still in a plastic or pulpy condition.

In supplying the fibres, I provide means whereby some of the fibres will be sup lied crosswise of the sheet of fabric, and whereby other fibres will be supplied to the sheet lengthwise thereof, so that the fibres-will strengthen and reenforce the sheet in both directions, thus greatly increasing the tensile strength of the composite sheet.

By applying the fibres while the fabric is still in pulp condition, the fibres be come embedded 1n the mass of the pulp, and become firmly united therewith, so that in the composite sheet they extend in both directions of the sheet and are firmly embedded in the pulp, and form a very strong tough sheet, which ofi'ers a strong resistance to tearing in any direction.

Referring now to Fig. 1, the apparatus shown therein comprises a series of pulp tanks or vats 10 and 11 (any number of pulp tanks may be used depending on what thickness of fabric is desired) a series of rotatable cylindrical screens 12 and 13, operating in the pulp tanks, and an endless web 1 1, which may be of felt, onto which the revolving cylinders 12 and 13 successively deposit layers of pulp. This part of the apparatus is old and well-known in the art, a detailed description of similar apparatus bein found in chapter 25 of a book entitle Asphalt and Allied Substances by Herbert Abraham, copyright 1918 byD. Van Nostrand Co.

In the pperation of this machine, the pulp wh ch may be ground-up rag fibres, or any suitable material, is suspended in water in the tanks 10 and 11, and as the j cylindrical screens 12 and 13, rotate as indicated by the direction of the arrows, each cyl nder plcks up a layer of the fibrous pulp, as indicated at 15 and 16, and these layers 15 and 16 are deposited on the felt web 14, this web being pressed against the cylinders 12 and 13, by means of rollers 17 and 18.

The relative adhesive and cohesive properties of the pulp, web and screens is such that the films of pulp adhere to the web 14 rather than to the screens, so that the films of pulp are removed from the screens and adhere to the web and travel along with the web.

A suction box is provided at 19 to assist in removing an surplus water which may have been carried along with the nip. The part of the apparatus thus far scribed is old and well-known in the art, and commonly used for preparing felted fabrics.

However, I combine with the apparatus described, means 20 and 21 for supplying fibres such as sisal or other fibre to the fi of pulp, while thefilm is still in a plastic condition. The means 20 supply the fibre to e plastic film crosswise of the film as indicated at 22, while the means 21 supply the fibre lengthwise of the film as indicated at 23.

The nature of the resulting fabric is shown in Fig. 2, which-shows the fibres 22 and 23 embedded in the pulp material 24, the fibres 22 extending in one-direction, and the fibres 23 extending crosswise of the fibres 22, all of the fibres being thoroughly embedded in the pulp 24, thus strengthening and reenforcing the fabric in every direction, and increasing the tensile strength very materially.

Afterward, the composite sheet may be treated in any suitable manner tofit it for use for which it is intended, that is to say, it may be saturated or coated with bituminous composition, such as asphalt compound,

to be used for roofing or waterproofing, or

it may be impregnated or coated with wax 'or parae or other suitable composition, or-

it may be used without further treatment for material for boxes and the like.

A greater or less number of revolving screens than the nber shown may be used, depending on the use to which the material isto be put. For making boxes, two or more layers of pulp and two or more layers of fibre may be used or one of the layers of fibre bein on the outside. 4

lFi. 3 s ows a sheet formed by apparatus in wich three revolvin screens are used,

- three layers of pulp being deposited on a traveling web, the crosswise fibres 22 being fed in between the first and second layers of ulp, and the lengthwise extending fibres 23 '1 ing fed in between the second and third la ers of pulp,

sing the fibre reenforcement as described, a cheaper grade of ulp, can be used than is ordinarily used, as t e fibre supplies the necessary tensile strength in both direc- Y tions, making up for the low tensile strength of the low grade pul used. It will be noted 7 that l can use for te manufacture ofthis Straw Having thus described my invention, what fabric, ap aratus such as is already used in the nu acture of paper, simply substituting for one or more of the vats, apparatus for distributing and aplying the fibrous heg i1 intense forming a plastic film of pulp, means for applying fibre to said plastic film substantially crosswise thereof,- and means for applying fibre to said plastic film substantially lengthwise thereof. I

2. An apparatus for forming a composite sheet comprising means for continuously forming a plastic film of pulp, means for a plying fibre to said plastic film substantial y lengthwise thereof, and means for applying fibre to said plastic film substantially crosswise thereof, said means for forming a plastic film comprising a-pulp tank, a rotatable cylindrical screen operating in said pulp tank, and a web on which said screen deposits a film of ulp, one of said fibre aplying meansacting to deliver fibre to said till formed of plastic material havingeinbedded therein fibres extending both lengthwise and crosswise of said film.-

5. An apparatus for forming a composite sheet, comprising means for continuously folng a plastic m of pulp, means for applying fibre to one side of said lastic film substantially crosswise thereo, and

to l

means for applfiying fibre to the other side of said plastic lm substantially lengthwise thereof.

'6. A method of forum a com osite sheet comprising making a film of p astic pul v and applymg fibre to one side of said an! crosswise thereof, and to the other side lengthwise thereof, while the than is still plastic.

7. A com osite sheet comprising a lliii'fle formed of p astic material, having bedded therein on one side thereof fibres entendin lengthwise thereof and having imbedde therein on the other side thereof fibres extending crosswise thereof.

In witness whereof, l have hereunto subscribed my name. 

